Railway track circuits



June 30; 1931. B. MISHELEVICH RAILWAY TRACKf CIRCUITS Filed July 17,1950

INVENTOR M AT oRNEf BENJAMIN, MISHELEVIGH, or PITTSBURGH, PEfi'NSYLVANIA, ASSIGNOR TO HE 1 UNIoN SWITCH & SIGNAL COMPANY, or swIssvALE, PENNSYLVANIA, A conrom- 1 I;

'I'ION 0F IPIEININSYIZVAIYITA j g I "AFRAII WAY'TRAGK CIRCUITS p Application filed July 17, 1930; Serial No. 468,500; I

My invention relates to'railway track circuits, and has for an ob ect theprovislon of I means for reducing thetimesrequired for the release of a track relay armature when a train enters the associated sectlon; r I I will describe one form of track circuit embodying my invention, andwill then point.

out the novel features thereof in claims;

The accompanying drawing'is adiagrarnlnatic View showing one form of track circuit embodying my invention. 7 7V 7 Referring to the drawing, the reference characters 1 and 1 designate the track rails of a railway which rails are divided by insulated joints 2 to provide a track section A'-B.

The reference character R designates a track relay having an armature. 5 pivotally mounted at 5* and biased by gravity to its,

open position Whereina front contact 6 6 is open. The relay includes a main wlndlng 3 for closing the armature 5 against the ELIOT/1011 of gravity, and an auxiliary winding 4 for creating in the armature a flux which .op-

'R. The current flowing poses the flux created by the main winding 3. l G is the usual source of track circuit current connected" across the rails of section AB through the usual current limiting impedance 8. The main winding 3 of relay R is connected across the rails of section'A B; s

Auxiliary winding 4 is connected across the rails of section A*B in series with a source of current which as here shown 1s a battery C and in series with contact 66 -of relay hrough winding fl opposes the track circuit current. f

The parts are so proportioned that when the track section is unoccupied, the flux createdby winding'3 is" considerably greater than the flux created by winding 4, and that the resultant flux issufiicient'tof close the armature 5. When the train enters section A-B, however, the wheels and axles will form a low resistance shunt across the'rails, so that the main winding 3- will be substantial'ly deenergized, and the flux due'tdwind- 1 and this reversal will cause the armature to release more quickly than if the auxiliary i W 1IldlI1g4 with battery-C were not provided; The relay will remain open while the track section AB isoccupied because the flux in winding 3 is/substantially zero due I to the low resistance shunt caused by-the,

wheels and axles of the train, andthe flux 1n w nding 4 is z'ero'd-uefto the open circuit at contact 6+6. Due to the open c'ircuit at contact 6-6 ,'no power istaken from bat tery C while" the track section A. B is occupied. V I

- One feature of my invention is that-the quick release of the track relay is accom-' plished Without the necessity for line wires running through the section.

Although-Thrive herein' shown and de i scribed only one form of track circuit em bodying my invention, it is understood that i various changes and modifications maybe made therein within the scope of the appended claims, without departing frolnthe spirit and scope of my, invention. 1 I v "Having thus described myinvention, what IClalm-1S; f v

I 1. In comb1nat1on, -a section of railway track, a source of current; connected across the rails at one end of said section, a relay I having two cooperatingwvlndings, a connection:acrosstherails at the other endiof' said 1 section including one of said windings, and

a second connection across the rails at the latter end 'ofsai'd' section including the other of said windings and a second source of current as' well as a front contact of said relay.

2. In combination, a section of railway track, a'source of current connected across the rails at one end of said section, a relay having an armaturebiased by gravity to winding for creating in said armature a flux the open position and a main winding for closlng said armature as well as an auxiliary which opposes and is Weaker than the flux created therein by said main Winding, a connection across the rails at the other end of said section including said main Winding, and a second connection across the rails at the latter end of said section including the other of said windings and a second source of current as well as a front contact of said relay.

In testimony whereof I afiix my signature.

BENJAMIN MISHELEVICH. 

